In recent years, for example, as the sizes of flat panel displays (FPDs) such as liquid crystal panels increase, the flat panel displays require members having large areas thereof on which high-precision micromachining process is performed in the order of μm or less. Further, micromachining of a large role mold for making a sheet, a mold having a fine shape for a deep micro, lens and a flat-end groove, difficult-to-machine materials or the like, which are difficult to make by conventional machining processes, is now considered in various manners.
On the other hand, for example, it is known to be able to easily form a micro pattern of 1 μm or less on a surface of metal by abrasion machining using an ultra-short pulse laser beam whose pulse width is in the order of picosecond (ps) or less. Heretofore, various methods have been presented with regard to a technique for machining a surface of an object made of polymeric materials including resin, semiconductor material, glass material, metal material, and the like, by this ultra-short pulse laser machining (for example, see Patent Literature 1).
In the laser machining disclosed in Patent Literature 1, it is necessary to move and scan the object placed on a stage in a wide range in two-dimensional directions, i.e., XY directions. However, in this case, the machining speed is limited by the speed of movement of the stage, and it is difficult to increase the speed.
In the laser machining, there is a technique for micromachining a desired region by scanning the region two-dimensionally in XY directions with a laser beam, using a beam scanner such as Galvanometer scanner (for example, see Patent Literature 2). With the Galvanometer scanner, the scanning speed can be improved as compared with the use of the stage. However, in the techniques available today, the accuracy of positioning of the irradiation spot is 10 μm or more in the two-dimensional scanning of the pulse laser beam in this case, and it is difficult to apply this technique to the micromachining by abrasion process using the pulse laser beam.